Disazo dye.



UNITED STATES PATENT OFFICE.

KURT EESAMARI, OF 'ELBERFELD, AND ARTHUR ZART, F VOHWINKEIi, GERMANY,ASSIGNORS T0 FARBENFAB RIKEN VORM. FRIEDR. BAYER & 00., OF ELBERFELD,GERMANY, A CORPORATION OF GERMANY.

' DISAZO DYE.

Specification of Letters Patent.

Patented Feb. 4, 1913.

No Drawing. Original application filed July 27, 1911, Serial No.649,780. Divided and this application filed March 13, 1912. Serial No.683,586.

To all whom it may concern Be it known that we, KURT DESAMARI and ARTHURZART, doctors of philosophy,

chemists, citizens of the German Empire,

residing, respectively, at Elberfeld and Vohwinkel, Germany, haveinvented new and useful Improvements in Disazo Dye, of which thefollowing is a specification.

The present application which is a divisional application from ourapplication Serial No. 640780'filed July 27, 1911, concerns themanufacture and production of new azo colorin matters having mostprobably the following general formula:

R meaning a derivative of the 2-amino-5- I naphthol-7-sulfonic acidcontaining a heteronuclear ring:

7 sogn X meaning NHP, which may be replaced by O, and S..

The new dyes are obtained by combining the diazo compounds prepared fromaminophenyl-5-oxy-2- naphthimidazol 7 sulfonic acids with the?symmetrical urea obtained from 2-amino-5-naphthol-7 -sulfo1'1ic acid:

SOaH M SOaH NH-CO-NH- Of course two different molecules of thesecompounds can be used.

The new dyes are after being dried and pulverized in the shape of theiralkaline salts dark powders soluble in water; yielding upon reductionwith stannous chlorid and hydrochloric acid a derivative of 2-amino-5-naphthol-7-sulfonic acid containing a heteronuclear ring:

and a compound of the formula:

dyeing cotton red shades which on being developed with diazotizedpara-nitranilin change into shades fast to washing and capable of beingdischarged to a pure white.

The following example may further.

illustrate the invention, the parts being by weight :37 5 parts (1 mol.)of para-aminophenyl-5-oxy-12 naphthimidazol-7-sulfonic acidarediazotized with 69 parts of sodium nitrite and hydrochloric acid and inthe same manner 3'73 parts ofmeta-aminophenyl-5-oxy-1.2-naphthi-midazol-7-sulfonic acid arediazotized and both components are combined with 504 parts.,,of thesymmetrical urea of 2.5-aminonaphthol-7-sulionic acid containing anexcess of bicarbonate of sodium. After some time the wee s? mixture isheated and the dye is salted out" with common salt, filtered 0d anddried.

The new dye having most probably theformula:

Ill

is in the shape of its sodium salt a dark powder which is easily solublein water with a red coloration and which is soluble in concentratedsulfuric acid with a violet-red coloration. Upon reduction with stannouschlorid and hydrochloric acid it is split up intopara-aminophenyl-fi-oxy-1.2-naphthoxazol-Y-sulfonic acid,meta-aminophenyl-5- oxy-LQ-naphthimidazol-T-sulfonic acid, and thesymmetrical urea of 2.6-diamino-5-oxynaphthalene-'Z-siilfonic acid. Itdyes cotton red. The shade after being developed with diazotizedpara-nitranilin is blue-red fast to washing. It can be. discharged to apure white.

We claim:

1. The new .disazo dyestufis which are after being dried and pulverizedin the which is after being dried and pulverized in the shape of itssodium salt a dark powder soluble in concentrated sulfuric acid with ared coloration; yielding upon reduc-.

tion with sta-nnous chlorid and hydrochloric acid para aminophenyl 5 oxy1.2- naphthoiIazolJ-sulfonic acid, meta-aminophenyl5-oxy-1.2-naphthimidazol-7-sulfonic acid and the symmetrical urea of2.6-di amino 5 oxynaphthalene 7: sulfonic acid, dyeing cotton red, whichshade after being developed with diazotized para-nitranilin is dyeingcotton red shades which on being developed with diazotizedpara-nitranilin change to shades fast to washing and capable of beingdischarged to a pure white,

substantially as described.

2.. The new dye having most probably the formula bluish-red fast towashing which can be discharged to a pure white, substantially asdescribed.

testimony whereof we have hereunto set our hands in the scribingwitnesses.

Witnesses:

HELEN NUIER, ALBERT Norma.

presence of two sub-

